Analysis of Yangtze River Water as a Potential Source for Developing a Water Source Heat Pump in Chongqing

Characteristics of smoke flow and fire spread in a patio space of a high-rise building were studied to investigate their influences on fire compartment and safety evacuation. Fire development model was established and fire scenarios were designed to simulate fire and smoke spread by CFD software numerically based on concepts of fire performance-based design in a high-rise building with double patio space, whose height are 74. 65 m and 55. 95 m, respectively. Simulation results show that in all fire scenarios, performance targets for safety evacuation for people in each floor was satisfied, if smoke was extracted naturally using the patio space. Hang walls mounted in corridors around the patio space prevent smoke flowing out smoothly, shorten the coming of the risk time and increase fire danger. Using chimney effect, it is preferred to adopt natural smoke exhaust method in a high rise building with patio space.     

6个石榴品种的光合和蒸腾特性

为了提高石榴的品质及产量,利用美国Li-6400光合作用系统测定仪对芽变的软籽新品种白玉、白玉母本、玉石籽、大笨子、二笨子和薄皮糙6个石榴品种的光合速率、蒸腾速率等进行了研究,并对所测数据进行分析,结果表明:6个石榴品种的光补偿点变化范围为25~52μmol.m-2s-1,光饱和点变化范围为600~1 050μmol.m-2s-1,品种间相差较小;6个石榴品种的净光合速率日变化差别较大,其中4个品种为双峰型,并有"午休"现象,但"午休"时间不相同,二笨子和白玉母本为单峰型,并不出现"午休"现象。薄皮糙、大笨子、二笨子的蒸腾速率日变化曲线呈锯齿状,白玉母本和玉石籽为双峰曲线,白玉为单峰曲线。6个品种的胞间CO2浓度变化曲线类似"V"形。     

营养液浓度对水培马齿苋生长及品质的影响

以华南农业大学叶菜B配方营养液为标准溶液,比较了0.25、0.50、0.75、1.00倍浓度的营养液对马齿苋(Portulaca oleracea Linnaeus)的生长和品质的影响。结果表明,无论是从形态指标还是生理指标看,0.75倍均为最适宜马齿苋的营养液浓度。     

茶产业集聚的实证研究

产业集聚是经济发展过程中所表现出的一种空间聚集和地方专业化的经济现象。利用区位商LQ系数和产业地理集中指数对安徽省茶产业2002~2006年的集聚情况进行效益分析。结果表明,安徽茶产业具有明显的产业集聚现象,且主要集中在皖南和皖西地区,并通过其回归分析模型验证了茶产业的集聚水平与产业的发展高度正相关。     

Geochemical conditions in groundwater systems: Implications for the attenuation of agricultural nitrate

Nitrate resulting from nitrogen fertilisers used in Agriculture is a widespread contaminant of shallow groundwater and causes adverse effects on human, animal and ecosystem health. In order to evaluate the full extent of groundwater nitrate contamination, and how it might evolve in time, it is essential to understand controls on aquifer assimilative capacity. This level of understanding will also help to better target policies and incentives aimed at controlling the amount of nitrate entering downstream water systems.The potential for nitrate attenuation in groundwater was assessed by examining the concentration and distribution pattern of electron donors such as dissolved organic carbon (DOC), ferrous iron, and redox indicators such as dissolved oxygen (DO) and Eh in 57 monitoring bores on the lower Burdekin coastal floodplain, one of Queensland's and Australia's premier irrigation districts. Nitrate concentrations ranged from 0.1 to 14.4 mg/L NO₃-N but were mostly undetectable in bores close to the coast. Groundwater age dates suggest that while there are nitrate ‘hot spots’ in certain areas, some or most of the nitrate is being consumed on its way to the ocean. Low nitrate concentrations were coupled with high ferrous concentrations. The low DO concentrations (<2 mg/L) and high ferrous concentrations found in 55% of the bores indicate that redox conditions are suitable for nitrate attenuation by either denitrification or dissimilatory nitrate reduction to ammonium. The reducing environment may be associated with the high DOC concentrations (up to 82 mg C/L) found in these groundwaters. Furthermore, high levels of ferrous iron found in the Ayr area combined with the wide spread geographical distribution of DOC indicate that these areas have a high potential for sustaining geochemical processes that reduces nitrate levels. The distribution of geochemical indicators also suggests that the shallower depths (<15 m) of the groundwater systems have more potential for nitrate reduction than the deeper depths. The map identifying areas within the lower Burdekin with most potential for denitrification is a valuable first step in helping to understand and manage the fate of nitrate entering the groundwater.     

5种常用水产药物对胭脂鱼幼鱼的急性毒性研究

[目的]研究常用水产药物对胭脂鱼幼鱼的急性毒性。[方法]在室内常温、半静水条件下,采用硫酸铜、甲醛、氰戊菊酯、三唑磷和敌百虫开展对胭脂鱼幼鱼的急性毒性试验,分别在试验24、48、72和96 h后记录胭脂鱼幼鱼死亡数和试验药液的安全质量浓度。[结果]硫酸铜、甲醛、氰戊菊酯、三唑磷和敌百虫对胭脂鱼幼鱼96 h的LC50值分别为1.96、80.0、0.002、0.049和16.0 mg/L。胭脂鱼幼鱼对硫酸铜、甲醛、氰戊菊酯、三唑磷和敌百虫96h安全质量浓度分别为0.57、27.2、0.009、0.013和6.9 mg/L,5种药物对胭脂鱼幼鱼的毒性大小依次为氰戊菊酯、三唑磷、硫酸铜、敌百虫、甲醛,胭脂鱼幼鱼对氰戊菊酯、三唑磷、敌百虫具有一定的耐受性。[结论]该研究为胭脂鱼人工苗种繁育过程中合理用药防治病害提供了理论依据。     

Growth-Oriented Logging (GOL): A new concept towards sustainable forest management in Central Amazonian várzea floodplains

Against a background of increasing human populations in developing countries, and global climate change, conservation of tropical forests remains one of the most important ecological challenges of our time. One of the biggest difficulties for ecologically sustainable management of tropical forests is obtaining reliable growth data for trees, which is a prerequisite for determining harvesting volumes and cutting cycles. GOL is the first concept for sustainable management of tropical timber resources in Amazonian floodplain forests (várzea) based on species-specific management criteria, such as minimum logging diameters (MLDs) and cutting cycles. From timber species with varying wood densities of different successional stages, volume stocks have been estimated in 1-ha plots and 12 growth models have been developed based on tree rings, which are annually formed as a consequence of the regular, long-term flooding. The MLDs of timber species vary between 47 and 70 cm and the estimated cutting cycles differ the 10-fold, from 3 to 32 years. These enormous differences in the growth rates between tropical timber species are not considered in current management practices, which apply only one diameter cutting limit and one cutting cycle to harvest many tree species. This practice risks the overexploitation of slow-growing timber species, while the fast-growing timber species with low wood densities cannot be efficiently used. Based on the timber stocks and lifetime growth rates, the GOL concept has been created as an aid to improve forest management in the Central Amazonian várzea. The model is unique for tropical silviculture.     

溶氧浓度对植物青枯病高效生防菌株PBW1生长影响的研究

青枯病是危害大、分布广、损失重的植物病害之一。生防菌株PBW1对植物青枯病的防效可高达70％以上。本文研究了溶氧浓度对PBW1生长的影响, PBW1生长的临界溶氧浓度为25.5%;摇瓶与发酵罐培养的结果均表明,溶氧浓度越高,越有利于菌体的生长。     

中性红染色法检测人参皂苷及其衍生物对CEF增殖的影响

[目的]为体外研制人参皂苷及其衍生物的抗MDV作用机制提供理论依据.[方法]分别吸取各试验药物(人参皂苷、人参皂骨衍生物1～8,阳性对照盐酸吗啉胍)溶液0.5 ml至24孔细胞培养板第1孔中,然后1～10孔每孔加入0.5 ml细胞维持液,再将第1孔内液体混匀,吸取0.5 ml至第2孔内,再混匀,吸取0.5 ml至第3孔内,如此反复至第10孔.则药物的稀释倍数分别为21～210.其浓度分别是3.000 mg/ml,1.500 mg/ml,0.750 mg/ml,0.375 mg/ml,187.500μg/ml,93.750μg/ml,46.880μg/ml,23.440 μg/ml,11.720 μg/ml,5.860 μg/ml.采用中性红染料吸收法,检测人参皂苷及其衍生物对鸡胚成纤维细胞(CEF)体外培养中增殖活性的影响.试验中必须结合细胞病变观察法,通过在光镜下观察细胞的CPE,确定进行测定的最佳时间,以保证结果的准确性.具体操作如下:测定前2 h各孔加入50μl中性红染液,测定时倒掉孔内液体,用PBS洗细胞3次,每孔加入200μl脱色液,置微量振荡器上振荡10 min,使结晶溶解.然后用酶联免疫检测仪测定DD570值,作为细胞增殖的指标.OD值与活细胞的增殖呈正比,OD值越大,表明细胞增殖越旺盛.[结果]人参皂苷在大于750μg/ml浓度下对细胞有毒性,在5.86～46.88 μg/ml浓度下对细胞有促增殖作用.毒性作用在72 h下降,而促增殖作用在给药24 h后就表现出来.衍生物1在高浓度的4组均有毒性,OD值显著低于细胞对照组,但衍生物1的促增殖作用不明显.衍生物2在48～72 h分别有5～6组高浓度的OD值显著低于细胞对照组.衍生物3在高于187.5 μg/ml的浓度时,OD值低于细胞对照组,并且在72 h时,有2组OD值(11.72和5.86 μg/ml)高于细胞对照组,表现出促增殖作用.衍生物4的毒性较高,大部分孔的OD值显著低于正常对照组.衍生物5在浓度高于187.5 μg/ml时,OD值低于正常细胞对照组(P＜0.05),在24和72 h,分别有一组的OD值显著大于细胞对照组.衍生物6的毒性较大.衍生物7的促增殖作用较明显,从浓度93.75 μg/ml开始以后的OD值都大于细胞对照组,且在48 h有2组,72 h有3组显著大于细胞对照组.衍生物8在72 h时,低浓度表现出促增殖作用.盐酸吗啉胍没有促增殖作用,3 000 μg/ml浓度下与细胞对照组的OD值差异显著.可见,各药物的促增殖作用不完全相同,低毒性的药物促增殖作用更明显.从药物对CEF细胞的不同作用时间点来看,以72 h的OD值和正常对照的差异最大,在24 h和正常对照组差异不显著.[结论]人参皂苷及其衍生物在中、低浓度能够促进CEF细胞的增殖,且药物作用具有时间依赖性.     

SO2毒害水稻叶片吸收光谱植被指数研究

为寻找对SO_2伤害敏感的叶片吸收光谱植被指数,通过田间熏气试验对水稻叶片吸收光谱与叶绿素总量、熏气浓度的相关性进行了研究.结果表明,由吸收光谱曲线及其一阶导数光谱曲线的特征位置确定的分别位于蓝光区、黄光区和红光区的12个特征波段的叶片吸收光谱值均与叶绿素总量显著相关,由这些特征波段构建的植被指数BEACI/YEACI/REACI与叶绿素总量的相关性都达到极显著水平,并且相关系数比特征单波段吸收光谱值与叶绿素总量的相关性显著提高.进一步分析这些植被指数与SO_2熏气浓度之间的相关性表明,最新完全展开叶在663.239、693.460 nm的单波段吸收光谱以及植被指数BEACI、REACI、YEA CI613.385、YEACI_(630.036)和YEACI_(663.239)与SO_2熏气浓度呈正显著相关.BEACI、REACI,、YEACI_(613.385)、YEACI_(630.036)和YEACI_(663.229)为叶片吸收光谱SO_2伤害敏感植被指数,具有估测水稻SO_2伤害的应用潜力.